Fins are never called fins to she who must be obeyed .They are always called safety equipment.We must also remember that spending money on our beloved sport for safety is a relative thing . Try "darling youd never forgive yourself if i died because i lacked the proper safety equipment ,besides a hundred and four quid is a lot less than 3000 quid in burial costs isnt it "... pause then wait for her to say 'yes' and she will because if she loves you ,its the only thing she can say .If she doesnt love you she wont want to waste 3000 quid on a funeral ,will she . show the picture of the fins youve chosen with 2 colour options and say ,"which colour do you like best ,the black ones or the camo ones ?. when she says the camo one you say the magic words 'YES I THINK YOUR RIGHT' .(this will Gnaw at your soul, so you must practice this with conviction ,a mirror is good ,dont smile. you fail if you smile ). Then ,with great nonchalonce you say, "Ill see if I have time next week (not now) to pop in and get a good price ." Then walk away ,or casually put something away that she has been nagging you to take down too the shed (no more taliking ) Next week or sooner you go get what you want .Always tell her you got a discount of X amount .
Tell her you shopped around for the best price and then got a further discount on top.
The idea here is that women think of all mens sports as Hobbies ,like building model aeroplanes ,a waste of time and money .All the money is her money.She does the budget .Your just the bleeder of her budget .she needs a bargain ,a sign of great responsibility that you have spent her money wisely.
Having said all of this ,Im off to the Great Barrier reef in Australia to do a Scuba diving course, with one of my mates .Shes not coming. 9 Glorious dives on pristine coral crystal clear waters on a 29 metre diving boat .... my wife said I should !!!!