We went to Thailand in November on a BA ex-Milan ticket in Club World. Price was £1,500 each, which gets you BA's nice flat bed, in our case upstairs both ways.
Italy is still the cheapest place - outside Tripoli - to start a BA CW to Thailand but the price is now £1,800 and you need availability in D which can be tricky. You could build in a stopover like we did - we bought an EasyJet single to Milan and came back on the first leg of the BKK ticket, then went LHR-BKK two weeks later.
A business class connection to Phuket will be literally £55 each way, £30 in economy. You will get a long haul plane, probably - a bit of a novelty for an internal!