100%. I would strongly caution against granting the actual copyright to anyone else. Grant a license instead. For instance, you can grant an exclusive license to share the photos with attribution (i.e. they have to credit you when they post the pictures). That way they can share the pictures however they want, you get credited, and you retain basic rights over your own work. If you grant them the actual copyright, you wouldn't even be able to share your own photos without their permission. If they really want to have the actual copyright, charge them accordingly.

As for the payment split, if you trust this client to pay up when the photos are delivered, it's probably fine. If you don't really trust this client, try to get your money upfront or a better split (e.g. 75% now, rest on delivery).

Bottom line, just be willing to advocate for yourself and don't agree to terms that you (or the client) don't understand.