For about the past 8 years I've been using CrimeGuard 350i5----pretty much perfect IMHO. The entire system can be found for $50 or so, dirt plain simple and easy to install, very reliable all these years. Decent range for the remotes---I can arm/disarm mine in the driveway through house walls and windows, fresh batteries in the remotes of course.
These can and do function perfectly as an RKE, the alarm just an added feature.
It should be noted most of the more popular brand names are all made by the same company as CrimeGuard---paying more doesn't mean better quality in components. Features like remote start, paging capability etc etc etc do send prices upwards but even at that some models with a ton of features still won't run you over $250 if you're a DIY person.
For a lot of reasons remote start wouldn't work for me but even so there seem to be a lot of problems with them, even "professionally" installed. That's just one more reason I shy away from that option.