im new to the fixed gear scene and i dont have a bike yet. i see in some threads about frames that cost thousands of dollars and then there are the $200 bikesdirect framesets.. coming from bmx where the costs pretty much depend solely on material, where hi-tensil steel frames are the cheapest and are only found on low end complete bikes, then the more common 4130 chromoly frames that cost between $250-350, and finally the very uncommon titanium frames priced at around $1000.
whats the difference between a $200 bikesdirect frameset and a much more expensive frameset if they are of the same material?

The biggest differences in price are origin of manufacture and branding.

The frames used in at least one of the BD bikes is the SE Lager/Fuji Track/Dawes SST/Whatever bike snob has. The issue isn't really the quality of their bikes, it's more that they are shady as ****. Most of their frames are pretty much stolen designs made in the same factory, badged with the names of brands that went out of buisness long ago that they reregistered.

i wouldn't say stolen, they're just paying the factory for frames. in turn the factory puts whatever decal they want on the frame.

It's like saying saturn is stealing designs from opel, when really they're one in the same (but in this case the factory isn't really owned by any of these bike companies

so basically were just paying more for the name?

Bikesdirect frames and budget entry-level frames are tig-welded from relatively low-grade steel in a factory in Asia and they have pretty poor detailing. More expensive frames are likely to be finished better (paint, details, etc) and outfitted with better components, but often come from the same factories.
If you see a frame for "thousands of dollars" you're probably talking about NJS keirin bikes. NJS is a Japanese agency that certifies bike parts used in keirin races. For whatever reason, only a handful of builders are certified to build NJS frames or parts so they are constantly in high demand, expensive. Of course, they're also beautiful bikes with excellent craftsmanship and exceptional finish work...

If the frame has cromoly tubing doesn't mean that it's "good" cromoly.

There's several grades. from seamed made from flat steel then rounded and welded all the way to the good stuff wich is drawn over manderal (D.O.M) this is made like you make a playdough shape.

Now even if it has a 4130 sticker on 1 tube it doesn't mean that the WHOLE frame is cromoly...it could be that ONE tube!

take time and look at the welds., ring the frame by flicking it with your finger nail from welded joint to welded joint. Does the pitch change? do it to several brands and you'll get an ear for it. as the pitch changes you'll find out about the frame if it's double butted or straight gauge.

There's plenty of ways to cheat people on building a crappy frame. Price isn't a total selling point...take several bikes for a ride! buy the one that works best for you in your budget. TRUST your local shop most shops are good guys!