Vet shop, ask about pricing and their success rate. I priced vets on the eastern side of Colorado and they priced me at 1000 to 2000 a try. Priced one on the western side of Colorado who has had a 95% (because I made a decision against the vet's advice) success rate for me who has cost from 60 to 400 total. Best thing to do is call. 

We got out 16 year old maiden mare in foal first try last year, she's due in a couple of weeks

I went to a vet with the most experience........caught on first try!  I didn't check $$$ I was more concerned about repro experience

Roughly $350-400 per cycle here. That includes all ultrasounds, drugs if needed, the actual insemination process and preg check. We also have stalls to board mares until they’re confirmed in foal, so my husband can ultrasound or AI whenever he needs to or if the semen arrives late at night (gotta love midnight breedings).

ETA: just because someone has a high success rate doesn’t mean they should be allowed to charge an exorbitant amount. There’s a fine line between providing a successful service at a reasonable fee and gouging people because you know they’ll pay for it. Pretty soon they won’t keep coming back, even if their mares did get in foal.

I bred my 12 y/o maiden last year. 

I had a breeding soundness exam done in March. This included an ultrasound to determine where she was in her cycle. He recommended we put her on regumate so that I could be more in the ball park with her ovulating when I took her to be bred. If I am recalling correctly, I started the regumate about April 4th, April 25th or so I took her to the vet and he did an ultrasound. She had a large follicle on one side he said should ovulate in 3-5 days. She had another small one on the other side he said would likely go away. He sent me to the stud's farm with a couple shots of something to be given to her a few hours after she was covered to help push out any bacteria or excess fluid to try and prevent infection. Left those shots and the mare with the stud farm. They let her settle in that day and the next, and I think I took her on Wednesday. They teased and bred her Friday, she took him again Sunday. They wanted to keep her until she refused the stallion, so I left her there until Tuesday. She covered a 3rd time. After I got off the phone with the stud owner on Tuesday I called the vet. He said if she hadn't ovulated by now, something was up. Not necessarily bad, but just, up. He told me to go get her, so I did. I picked her up Tuesday afternoon (after her 3rd cover in 1 cycle) and took her straight to the vet. He US'd her and the follicle he thought would ovulate didn't, it had stopped growing, but the other one was like a 50 (going from memory - but it was huge.) He gave her a shot of oxytocin to cause ovulation and sent me home. 16 days later she was confirmed in foal with 1 baby, and she's due any day now.

All that to say, I am the type of person who was SUPER grateful the route we went. Im glad we put her on regumate so I wasn't guessing at her cycle (she is a hussy in full fledged heat, but I had noticed she'd do it like every other week, so I wasn't ever confident where she was. I was MOST grateful he told me to bring her home and US'd her again and gave her the oxy to cycle. If I breed her again, whether it be A/I or whatever, I'd go the same route. I'd put her on regumate and US around day 20. 

The breeding soundness exam was maybe $150 (including farm call), the regumate was about $50. The US before I took her was $60 and I took her to him, and the US when I brought her back was $60 also. So, excluding stud fee, it took me around $300 to get her in foal with live cover.