As mentioned above, EVERYONE here loves to spend your money! A lot depends on what you want to do (as mentioned above). You can do little stuff on a bigger mill, but it can be really tough to do the converse. I'd get the biggest your shop can handle. I've had a Grizzly round column mill (~8 x 30 table, 700 lbs.), have a Jet JVM-830 small knee mill (8 x 30 table, ~1000 lbs.) an Atlas MFB horizontal mill (350 lbs.), a Bridgeport (9 x 42 table, ~2000 lbs.), and a Tormach 1100 (9 x 24 table, ~1300 lbs.). Bought the Grizzly new, others were used.
New is very nice as you will have a pristine table and most likely no hidden issues. However, they typically do not include much if any tooling. You can easily spend half again as much on tooling: Vise, clamping kit, collets, edge-finder, parallels, end mills, drill chuck, measuring tools, etc. Most of the time used mills come with some tooling.
If you are looking for used, hit the web site
www.searchtempest.com. It's a Craig's List/ eBay/ Amazon search engine. Give it a search title, price range, and max drive distance and you'll have plenty of options. I listed a few in the area around you (give or take a state). Some around your budget, some a bit higher.
Personally, you can't beat a Bridgeport-sized knee mill. But it's literally a ton of iron so you'll need the infrastructure to move it. There are a plethora of parts and accessories out there. The market didn't lead to dozens of import knock-offs without good reason. BP-sized machines are generally 3 phase power, so budget another $100 - $300 for a static phase converter or Variable Frequency Drive unit. Good Hunting!
Bruce
Decent looking Enco small BP clone for $4K. No tooling, but power feeds on X, Y and Z plus a 2-axis old DRO
2001 enco knee milling machine. Can load it on your trailer, 1,750lb. Coolant pump were removed. 3ph motor, can be running on single phase with a converter. X Y digital read out. Z axis read out. 3...
grandisland.craigslist.org
Another Enco small BP close for $3K. Comes with a vise, collets, clamping kit, 3 face mills, 2 drill chucks, power feed on the X and an old 2-axis DRO.
Enco Milling Machine 8" x 36" Table X Axis Power Feed 10 Spindle Speeds, Two Speed Motor Low Range...
semo.craigslist.org
Nice looking real-deal Bridgeport with a 1 1/2 HP variable speed head, $3500. Comes with power feed on the X, no other tooling though it has a drill chuck in the spindle.
Nice little 9 x 36 Bridgeport milling machine. Variable speed head great looking hard chrome ways power feed automatic lube.
stlouis.craigslist.org
Nice looking Bridgeport 1 HP step-pulley machine for $1500 (same seller as above). Power feed on X, drill chuck in the spindle.
Nice milling machine has power feed runs well.
stlouis.craigslist.org