DIY isn't so hard. The hardest part of DIY is temperature control, and this is easily handled with a large tub of tempered water. Sure, there are startup costs to consider, but these are minimal and will be amortized in short order. HC-110 is a very good and economical developer for processing sheet film in trays. Kodak's Flexicolor Fixer and Replenisher is an excellent, non-hardening fixer when used at 1/2 strength for all sorts of B&W materials even though it was made for color negatives. Stop bath and Photoflo are dirt cheap. Trays large enough to handle a 5x7 print are big enough and these are selling for very little on the used market. You can even use food storage containers of an appropriate size, source from your local favorite housewares department. A good thermometer is a must,but even that's not too expensive. I use an electronic kitchen thermometer sourced for about $10 from WalMart and it's more than good enough for B&W work. Run a string above the bathtub and add a few spring clamp type clothes pins to hang your film to dry and you're done. After the first 100 or so negatives processed, you'll have been paid back, probably with some money left over. Printing is where it starts to get expensive, but you might not be so keen to print all your negatives.