I think playing a successful hero warrior with relies ONLY on buyable preps is very doable, especially if you plan ahead and design a build better suited for doing so.

I tend to put preps into two categories: survivability and buff. Fly, enlarge/reduce, recall, teleport, etc. are all necessary to stay alive and safely fight the most basic of fights. With these things, you can do a lot. Tack on Squire protection by cabal power and you've got yourself some DR.

Stoneskin, aura, shield, resists, and other various things make you able to go toe to toe with tougher foes and/or foes that are willing to spend the time getting those things. You'll get more kills and die less and overall by more of a mofo.

The important thing is that the first group is mandatory (IMHO), but very easy to cover all the time. The latter isn't mandatory to being relatively successful, as long as you're not hoping to top Kostyan's PK record, but take more knowledge and, this is the part I dislike, time.

Without a jazzy prep bag you're not likely to beat on Scion Invoker or prepped lions, etc., but you should be able to bag a few kills, avoid most deaths, and generally contribute to cabal defense, etc.