You probably have another little known option available.  The 750 can accept RTCM correction like the 500 and 250.  That is beacon correction, and I think that there are 3 stations on the Portuguese coast.  Search this site for beacon correction into a 500.  You need an AGPS 132 send the corrections to the 750(I asked a Trimble tech at the last Tulare, CA Ag Expo if the 750 has this capability).  What you get is a better correction if the beacon is close.  Also, since it is not a space based correction system, beacon correction is pretty close to being immune to solar flare problems.  There is a 132 on Ebay right now.  It has firmware version 3.06 so it has the latest motherboard.

I also think that a Raven 210 receiver can send the required corrections.  One of those would be really cheap since the 210 is a miserable receiver. I have two that sit on the "healing" shelf.  That would not be an issue in this case, all the receiver does is relay the beacon corrections.