Rmance, I just went through this process. I tried a lot of different angles. In the end, I had two viable approaches, and a possible third approach. I used Option #2.
Option #1: Buy Used Through Sportsmobile TX or Sportsmobile North
(I did not end up using this option)
Both SMB TX and N have relationships with Bank of the West, and are able to obtain financing for their used rigs in this manner. Typically, this only works with the vehicles they physically have on display at one of the two locations, and that usually means a vehicle that is less than 10 years old.
Option #2: NADA Value; Credit Union or Bank Loan
(This is what I did)
This option takes more work, more patience, and potentially more cash.
First--Banks and credit unions will loan money for RVs based on their NADA values. SMBs are listed in the NADA RV guide. (Homebuilds do not qualify.)
The NADA value shown for most RVs in the US actually exceeds that vehicle's street price. This is generally the opposite for specialized Class B RVs, such as SMBs and Roadtreks. Street price for these vehicles is often higher than the listed NADA value. The reason for this is that NADA doesn't actually care what the street value of a vehicle is. They have a mathematical depreciation formula that they apply across the board to all RVs. They start with the list price, and then depreciate according to their formula on an annual basis. It has nothing to do with reality, but it makes the actuaries happy. Go figure.
NADA value is workable with SMBs--sorta--if you know how to work the system.
Challenge #1: NADA does not accommodate 4x4 SMBs until 2010. This means that every pre-2010 SMB is priced as if it were 2WD. There is nothing you can do about this.
If you are buying a 2010 or newer:
1. You can buy either a 2WD or a 4x4 SMB.
2. NADA value will probably be less than street value, so your down payment will need to fill in the gap. But you will get a loan for most of the purchase cost.
3. You can work the system to increase the NADA value. (I'll address this in a minute.)
If you are buying a 2009 or older (I bought a 2006):
1. NADA value will come up short, as usual.
2. NADA value for a 4x4 will come up an additional $15K - $20K short because they do not take the 4x4 conversion into account.
3. You can still work the system to increase NADA value. I'll talk about this below.
4. Bottom line: for a 2WD rig, this is the same as the 2010 and newer situation. NADA value will come up a little short, but you can get a loan for most of the purchase price.
5. If you want a 4x4, you have two choices:
a) buy a 2WD rig, get most of it financed, and pay separately to get it converted to 4WD. (This is what I am doing. The benefit to this is that I get to choose which conversion I want, and the conversion is 100% new for me.)
b) Buy a 4x4 rig, and pay a much larger down payment.
Sidenote #1: How to work the NADA system to increase rated value:
NADA starts with a set base value. They then add value for options. If you pick through the list of options on line, you can very rapidly figure out which options will add the most value to your rig. For example, they have an option called "Full Body Paint." There is no definition for this, but I believe this applies to RVs that have a fully painted exterior, as opposed to being fiberglass covered with vinyl striping. Full Body Paint is good for an additional $4K - $8K, depending on the rig. SMBs definitely have full exterior paint, so I ticked this box when I filled out my loan paperwork.
Bottom line: do your homework in advance. Make sure that you figure out which options NADA lists for your rig, and make sure that you get credit for every one of those options. It will help your value. When you go in to apply for your loan, come in with a sheet of paper that lists each one of those options, using the exact language that NADA uses. Hand that to your loan officer. That will ensure that all of those boxes get ticked as they are calculating your NADA value.
Possible Option #3: Appraisal (This MIGHT work, but it is pretty much a Hail Mary pass)
Some banks will sometimes accept an independent appraisal of your rig in the event that the selling price is different from the NADA value. I could write a book on how to get through the appraisal process, and I'm not going to do that here. Suffice to say that at one point I came close to buying an SMB, and I was going to use the appraisal route. My draft appraisal documentation came to well over 50 pages, and that was only the beginning of the draft.
Sidenote #2: NADA actually has records of many RVs by VIN. For example, when I did my loan for my 2006, my loan officer was able to find my VIN in NADA's database. That made my credit union happy, and it gave us a base value for the vehicle. To that, I added my list of options--the options were not included in the base value. By the time I was done, the NADA value was more than my purchase price. Happy me!
Of course, this was for a 2WD rig. I just wrote a check to Quadvan for my 4x4 conversion, so I didn't get away scot-free.
Good luck with your search! These dang things are expensive, but they sure are fun!