That was my secondary option. Do you have any good mill suggestions for that price range I should look for
After a lot of evaluation, I targeted - and tried to buy - a "Diamond" mill with sliding head. Foolishly, I overlooked the more common Nichols and bought $300 worth of Burke # 4 /B-100-4 that was missing its original geared-head motor. PO threw in a couple of boxes of tooling as we loaded-out. Once I got around to assessing it, "enough" of it seem usable I sent him another hundred bucks. Bought a larger mill since, so the Burke languished.
For your use, work in the turning range of an SB 9, I'd look for a Whitney, Rockford, Burke, Hardinge Cataract or such. MUCH cheaper than the coveted TU/TM Hardinge.
There was a Cataract on ebay a short time ago at under $500. Bidding is still ongoing and just a tad above that:
Vintage Hardinge Bros. Cataract Bench Top Miller 3C Collet Milling | eBay
It even uses the same 3C collets as an SB 9 and takes up not a lot more space than a minibar fridge.
The whole tribe of small horizontals are waay too brute-simple to whine about restoral effort. There just isn't much THERE to go wrong, nor take long to put back right. Flat belt cone-head or vee-belts, few or no gears, etc.
Even so, within their work envelope, they are genuine, JFDI, MILLING MACHINES, not spaghetti-sloppy "adapters", and are capable of superb and enduring accuracy that makes a too-many-movable-joints BeePee vertical struggle - hard - to match.
BIG horizontals? Love em for their power, but can be a pain to literally "get your head around". And/or want rather MASSIVE angle plates.
SMALL ones? Not so much trouble.
Little bugger gives you grief as to laying an eyeball on the work or cutter? Just put caster wheels or a lazy-susan style turntable under it .. or ball-socket it to the wall, "Panavise" style!
The work is clamped to the mill, after all, and THAT part ain't allowing relative movement, even if the whole rig was hung out of a corner closet off a swing-arm fabbed of barnyard gate hinges.