The salary is very decent.
The wordings in the email are a bit confusing though.
You can say you are happy with the higher end of their range along with a relocation package.
The higher end of their range is 100K, which also falls within the range you requested originally. So it doesn't look like you are now revaluing yourself all of a sudden.
Negotiate a relocation package. Any decent company will/should offer some form of relocation support. The usual deal is a couple of months of temporary accommodation, a dedicated relocation agent, and/or some cash in hand to get you started.
Good luck!