You can get a monthly subscription that you can turn on and off as needed, this is what I do and although is a bit more expensive than an annual subscription it suites me.
I find it generally quite a good site, but do check everything at least twice if taking info from other people FT research as once an error occurs it can get re-posted many times.
Also worth looking at how many relatives people have in their FT, if it is a few hundred then is probably their own work and will probably be accurate. If it is many thousands then the data has probably been harvested indiscriminately an I would treat with great care.
