Do interfaces include DIs and preamps these days or is it necessary to buy each one seperately?

Fairly basic question, I know, but I'm just starting off. I've been reading up on how to record for about a month now, but I just got more confused. I have my guitar, bass, mic, amp, computer, etc. I just need to figure out how to plug my equipment into the computer so I can hit record. I'm not looking to spend more than $250 on each piece of equipment. I don't need a lot of inputs, I can afford to record one piece at a time, so I'd prefer quality and simplicity over bells and whistles and less quality.
Generally, if it includes mic preamps, it'll have at least one built-in DI, but that's not ALWAYS the case... for the lower end ones, though, it's pretty common practice.

Something like a Focusrite Scarlett 2i4 will be just fine for what you need.
Quote by Dave_Mc
I've had tube amps for a while now, but never actually had any go down on me
Quote by jj1565
maybe you're not saying the right things? an amp likes to know you care.

Most of them do have DIs now, although some people prefer to upgrade the DI with a Countryman or a Radial Passive. Not sure if it is worth the price difference as you can buy slightly better interface for say another $50 and save a few bucks in the process.

Look up PreSonus Audiobox as well, I haven't had issues with their DIs.
Just picked up a FocusRite Scarlett. Found a really good deal for $79.00 new. Looking forward to recording. Thanks guys!