Buy where you can return!
I've found that inexpensive mic preamps ($200.00 range) tend to be disappointing in their performance and some are quite noisy, especially those with tubes. A lot depends on your mixer. If your using a mackie, or other high quality board, you may find that an inexpensive outboard preamp has little good effect on your sound. If your mixer is a budget model, you may notice some improvement with a preamp.
There is a really good thread, I believe its under "other equipment reviews", regarding the presonus blue tube that you might want to check out. The posts there seem to indicate a less than stellar performance from that particular preamp.
Whatever you decide, be sure to buy somewhere that allows you to return equipment that doesn't perform up to your expectations. That is one of the benefits of shopping at a place like Guitar Centers (30 days to return-no questions asked). This way, you can take several preamps home and try them out to see which one gives you the most improvement in sound.
Hope this helps... bigbear
