Well it's hands down that Yamaha & Honda are tops in reliability. So to limit any potential problems I would recommend going with one of these.

If your looking to stay under $4K in the used 400cc class, you can pretty much have your pick of any model made before 2004/5.

But in order to get better specific recommendations you'll need to give a little more information. Such as what you want it to do. Automatic trans or manual? 2WD or 4WD? Utility or sport? Farm chores? Hunting? Muddin?
Pull a trailer? Trail riding? Sand dunes?

I currently have a 2005 Yamaha Bruin (Camo +, 4X4, Auto). It has done everything I have asked of it. Trail riding. Some light mudding (I don't like to clean muddy machines). Hill climbing. Snow plowing. Farm chores, pulling a severely overloaded trailer doing food plots. Hunting? Heck ya! Weshotgun deer hunt in southern IL where the fields are kinda like carbonatedclay. Had no problem dragging a couple of deer with guys on front and back racks.

I was kinda wondering how it would be without a low range, but even plowing snow, I've got NO COMPLAINTS. Everyone who's ridden it seems to really dig it.

A really great thing about staying in the 400cc class(maybe up to 500) is that the machines are not super big and heavy. The smaller machines aremuch more nimble in the woods, able to squeeze thru smaller openings and such. Better on fuel economy. I have actually ridden aroundmuch bigger, heavier machines bogged down in mud and winched them out.

There'sALOT of used machines out there for sale by guys who just didn't use themas much as they thought they would. You should have no problem getting agood (or even super) deal.

As to deals on a new machine? Let your fingers do the walking! Make the phone calls, get the trader mags and look for brand new 2005 (or even 2004) models as 2006's are on the floor now and no dealer wants old inventory on their books - just better to deal and get them out of inventory. "Cut the losses".

As a matter of fact, it's a really nice sunny day here asI'm looking out onmy driveway at mine on the trailer. I think I'll hook it up to the truck and take it out!