macro decision time..sony or sigma?

1) Im not sure if the maths in this case is so simple..

2) If I would be worried about the costs, I would run away from photography completely (I guess it generally is very expensive)...yep, I know all these things, dont worry, got a nice tripod, will get a ring flash (I dont consider 300 for it as a mega-heavy-investment) expensive exotic vacations? All I need is to visit my parents house in the country, its garden is a microcosmos of its own..could spend months there co catch all the mini-beasts in there

There are more expensive photography disciplines than macro, lets say underwater...the prices for the housings are ridiculous, Im deciding if I will buy the new UK-GERMANY A99 housing for my upcoming vacation, it would be around 2 grand! or I will stick to my super-cheap meike NEX5n housing (in which I actually baked the shutter last time because of NEXs overheating and condensation)

but thanks for the reply anyway and no, you didnt scare me