Tom's suggestion on 87-91 is excellent good since it meets your price
range and avoids the optispark woes of the early LT-1 engines. (Precise
ignition timing but subject to damage from coolant leaks.)
If you are looking for a six speed then it's 89-91. (Six-speed manual
arrived on the 89s.)  90 is an excellent choice--bit more refined &
better displays than 89.

If you enjoy 'old fashioned' wrench-bending as a labor of love, you
might do well with a late C3 -- good car to 'grow old with.'  These cars
won't go out of style and there will still be well-cared-for C3s on the
road when all of the C4s are retired.  They were just starting into
computerized but carburetted engine control and in some states, smog can
be problematic.  Late C3s and very early C4s were short on thermal
insulation in cockpit (fixable).

If you're talking daily driver, the gasoline bills will be lower with a
C4 and the performance much better.  I commute in my '89 (auto) and
average 21-22 mpg mixed city-freeway, 24 hwy.  (C5 does even better).
L98 engine on C4s has excellent torque off the line but the torque and
horsepower peak around 4K.  The LT-1 engine has just a tad more torque
but it peaks later for more horsepower and higher top speed.  LT-4 in a
'96 is the best of the bunch but the prices on those take you into C5
territory.

The jobs you speak to are all doable with little fuss but you'll need to
carefully select a socket & drive for the plugs.  Get a factory shop
manual and pick up a Haynes as well (nice accessibility and tool tips
that Chevy/GM never thought of).  Also plenty of maintenance tips and
discussion on web sites.

Beyond 87, C4 alternator has plenty of reserve output but has poor
cooling between 20 and 35 mph.  If you much spend time in traffic, a.c.
on, you'll replace an alternator every other year.  Easy job.
(make/borrow a thin breaker bar for the belt tensioner.)  Brakes and the
rest of it have few surprises.

I've seen a couple of audio installations in C4s with an second
(externally vented) battery in the car to handle audio power peaks.  I
think they connected that with an RV style secondary battery charger.
That eases the burden on wiring and alternator.

Enjoy.
--
PJ
'89 auto-coupe  '02 e-blu 6spd