Cheap
Well, I hate to say it, but maybe the blue cloner could be a simple cheap option.
I cant guarantee it will work, but as a cheap option, its definately worth a try.
Try to get one with full functionality. (HID Prox, EM, AWID)
it wont really matter for what you want, for now, but you night as well get the best option.
DT no longer stock it, but this one
Modify it
Use your PM3 to remove the password if you need to later
Located in the “CONs” of this post, but thread provided for more information