Gamersgate sells the D&D Anthology (Baldur's gate 1+2 and all exansions; Icewind dale 1+2 and all expansions; and 2 other old school RPGs) for $20. These are the original games, and DRM free: http://www.gamersgate.com/DDB-DBAMC/dungeons-and-dragons-anthology-the-master-collection
But, you say, you're missing out on all the "Enhanced" content. The "Enhanced" content provided in this "Ehanced Edition" of Baldur's gate is available with several mods originally created for the original BGs. That is to say, "Baldur's Gate: Enhanced Edition" is essentially a compilation of preexisting mods already freely available to the Internet.
So, what are those mods?
1) There are two main conversion mods that string BG1 and BG2 together, and also run BG1 on the BG2 engine: Baldur's Gate Trilogy (BGT) and EasyTutu. Google these for more information, you have to use one or the other.
2) There's a "Lost Items" rebalancing mod I think is also essential. Since you're now playing BG1 on the BG2 engine, what happens if you pick "katana" as your weapon of choice at the start of BG1? There's no katanas throughout all of the original BG1, so you'd be up a creek with no... katana. This mod addresses this issue. It inserts BG2-specific items throughout the game (in a balanced way) so that you can play BG1 under a BG2 style character. It ALSO inserts other items that were very sparse (eg, axes) in the stock BG1 and BG2. http://www.shsforums.net/topic/16160-vedrans-lost-items/
3) Next, there's a display resolution fix called "G3: Widescreen Mod". The original BGs were restricted in their max resolutions. This mod increases the playable resolutions, including widescreens. http://www.gibberlings3.net/widescreen/
Those 3 mods are pretty much what this enhanced edition is (in fact, from what I've read it doesn't even have the "lost items" mod). Maybe there's some new cutscenes if you're into that. I just wanted to put this up here to help people make informed decisions. I'd also like to point out there are a TON of other mods of BGT and EasyTutu available out there.