A basic IDE controller only costs like $20 now. I'd say just stick a few of those in there. Not sure why you'd want 10 drives in a system without any sort of RAID setup though. Unless you just have a bunch of old drives you want to use.
there are cheap SATA cards too, a mobo with 4 SATA and three two-ports SATA cards (with Sil3114 controller, 17€ here) can host ten SATA drives (and you can use an IDE drive for OS + apps)
but, while checking prices on my usual online store I saw that 400GB samsung HDD is at 150€ only! price per GB in the same range as the "smaller" hard drives. it's IDE though.
so, with six disks you can have a software RAID 5 array with 2 "fake" TB capacity.
I think when you do that you'd better have one HDD per IDE channel, so you'd look at using the two mobo IDE ports + two IDE cards, or use three IDE cards for the array. and come around $/€ 1000, including the mobo, IDE cards and HDDs. nice file server in my opinion
3ware used to make some nice PCI ide cards that are just "dumb" but have a switched fabic. You can get an 3ware 5800 or 6800 on ebay cheap since they don't do hardware RAID, but you'll get 8 IDE drives on their own controllers.