yes you can enter the uk as many times as you like, but you cannot spend more than 6 months in the uk in any one trip, so if you did enter the uk for 6 months, in theory you should then leave the uk for 6 months before coming back again for 6 months, yes that way you probably wouldn't save much if any money, but as mentioned by yourself already you wouldn't need to go thru the visa process twice, only once and you wouldnt have to pay any increased fees,
but you would save money, if you came for 3 months, went back to the phils for 3 months, and kept doing this, but it would cost you alot more in air fares![]()