For one thing, you're looking at outdated prices. The current pass prices for adults are: Adult15 trips 465 Baht Average 31 Baht/trip
25 trips 725 Baht Average 29 Baht/trip
40 trips 1,080 Baht Average 27 Baht/trip
50 trips 1,300 Baht Average 26 Baht/trip
Source: https://www.bts.co.th/eng/tickets/ticket-rabbit-valueandtrips.html
Also, it's not a choice to either get a Rabbit card or get a multitrip pass. To get the multiple trips as quoted in the above rates, you have to get a rabbit card. They then put the multiple-trip package you choose on your Rabbit card
