my mom offers again

i finally told my mom about our fourth angel baby. i didnt go into much detail other that it was at 5 weeks again. she is convinced the hospital did something wrong when R was born via c section in 2007. there has to be something wrong with my womb. that what she thinks anyway.
anyway she offered to be my surrogate, again. and i am actually considering it.
i know there are risks with her age and it will take time to save the money. but i cant seem to carry a child. i need someone else to do it for me.
im not sure i will get any kind of fertility treatment on the NHS because we already have R.
The biker thinks its far too creepy to have my mom carry our child/children but i dont think it is. we need to have a long conversation on what we do next. because him not talking and pretending it isnt happening is not healthy for me, for him or for us.
im going to look up surrogacy and whats involved etc before i talk to him. see how much it costs.
if it isnt that then we will have to adopt. although the biker is now against that as well..............
i would really like some info from others who have maybe followed the surrogacy route or have any information on it at all. thankyou