They will be getting more from this yes.
But, you need to consider where the link will be, not just on what page of the site but where on that page.
Will it be on the footer, a side bar, in body content?
Also, how many other links are on that page, what text will be surrounding the link?
Mainly though, above the issues of the Moz Rank, etc... is the link of any vale through relevance? If it is of value to users then take it no matter what the MozRank is, if not, then you need to consider that they will be getting more out of it than you. Maybe suggest that your link is on their homepage, whilst the link you give to them is on a weaker page on your site.