Instead of paying and spend time learning another engine, just use that time to learn XNA. It will be the same time! At least it was with me, look:

http://br.youtube.com/watch?v=2LBz31EpBNA

http://br.youtube.com/watch?v=vd4R1JVXNAc

http://br.youtube.com/watch?v=jBQhxYNxI8U

http://br.youtube.com/watch?v=Q0MpSxyH-34

http://br.youtube.com/watch?v=jBQhxYNxI8U
http://br.youtube.com/watch?v=2LBz31EpBNA
http://br.youtube.com/watch?v=Q0MpSxyH-34
http://www.youtube.com/watch?v=vd4R1JVXNAc
http://www.youtube.com/watch?v=BvSG4_nOB88