Not the best deal ever but reasonable for anyone who is short of time to get the last few TPs for their year. During June (all I looked at) you can book a MAN-LHR-DUB-MAN for £297 giving you 120TP (£2.50/TPish). Leaving MAN at 4pm and land back just after 11pm too so not a huge time issue as well.
that wouldn’t be 120 TP. DUB-MAN is EI operated and does earn TP if booked under the BA codeshare. However there are no business selling classes so you’ll probably be in Y selling class and only earn 20 for that flight. TP would be 40+40+20.