Equal or better tonearm than Jelco for like amount of money

Nothing at that pricepoint. Groovemaster ll is worth a look, although, the Jelco 850 may win on detail where the GM has more authority. 

There are so many inexpensive vintage tonearm better than Jelco. 

Denon DA-401, Victor UA-7045, Sony PUA series 

for a bit more long Victor UA-7082
Fidelity Reseach FR-64s 

Victor 7045 and 7082 with VTA on the fly are great (if you can find a perfect sample). 

New, with removable heads hell, and in its price range Jelco was pretty much it

Groovemaster more less  targeted for low compliance designs

New Jelco series was more for modern medium or high compliance designs. Actually there is no substitution of current production with removable headshell. 

Jelco is definitelty NOT for high compliance cartridges, such arms must be 5g mass. Jelco mass is much higher, it’s for mid compliance, with heavier headshell can be used for high-ish compliance cartridges.

Thimas Schick tonearms available in "9 or "12 inch, removable headshells. Modest price.