C-ISAM or SQL?

I've been programming in (ansi) C for about a year, and I'm getting sick and tired of writing all the functions to sort and search through my data files. I stumbled across an ISAM package that came with our SCO dev. system (running SCO on an Altos/Acer 7000P), but it seems to have some confilcts with other software and 'breaks' under heavy user loads. But this software did open my eyes to the fact that I don't have to do all the tedious work I've been doing. Which brings me to my question: Should I just get C-ISAM or should I break down and get ESQL/C? I'm looking for a way to provide access to data in C in a manner that allows faster software development. I've seen an ISAM system, and it looks like it will work fine, but I keep hearing about SQL and wonder if it would be more advantageous to go that route. Unfortunately, price is an issue in this case. The lower the cost, the easier it will be for me to sell the idea to my bosses. I talked briefly with a sales rep from my local Informix office, but he wasn't able to provide me with the info I wanted. (He was a sales rep, not a tech :-)) If anyone has opinions on this, I'd love to hear about what you are doing with it and how its worked (or not worked) out for you. (Please send me E-mail: hopl0001@maroon.tc.umn.edu) I'm handling data that varies from a few dozen records to tens of thousands of records, and as few as 3 parts per record up to 40 parts per record, with user loads in the range of 1-10 at any given time, with peaks up to as much as 50 for a short* period of time. Thanks in advance for any info, Ben Hopland hopl0001@maroon.tc.umn.edu