I personnaly play lissandra she has a really low base mvm speed. and i always get 410 mvm speed at around 20 minutes. here's how i do it, and you should too. First off take free boots at 10 minutes...you dont really need mvm speed before do you ? Then take celerity. once you'll get your boots you'll be at 371, when you upgrade your boots ( which i always do after completing first item ) i get 391, then i go aether wisp and get 410, just sit on it, buy a rabadon, the game will probably end right there anyway. If not buy that Lich Bane its all good it gives more mana and CDR, plus you'll finaly do damage to turret with a lichbane, and for that one time you'll do an auto if you have one of the 3 haste item , plus rabadon plus lich bane , the proc is around 400 per auto... pretty good damage !
P.s. before the go to item was luddens, if you wanted mvm speed...there was only two option..luddens or lichbane... at least now you can have a cheap twin shadow if you are a bit behind but still want the mvm speed. so i dont udnerstand what you are complaining about.. you have more option then before... i don't get it ? plus you don't really need more then just he aether whisp to be fair ( if you take the rght runes )