Figure $5k for the boat. $1k for the HO, $1k for the ibr, $350 shipping, $250 setup, safety kit. Tax title is hard because varies so much. Trailer $800 or so. Give or take a couple hundred depending where u live.
you can't compare apple to apple w/ taxes and tags, since every state and many counties are even different.
However, most have paid right at MSRP for the Spark (my best local deal was $99 below MSRP), I managed a trailer w/ jack for $800 (Dealer List over $1K~, a Karavan 1250-46-L w/ torsion suspension)
The key thread in dealing for the Spark seems to be: "freight/setup and doc fees".
My dealer lists $795 setup/freight on Sparks ("since markup is so low") PLUS $150 doc fee for each title/registration. I managed to get those dropped to $495 (same as they charge for all other vehicles, ATV's, PWC's and the like) and $50 doc fee for Spark and $50 for trailer. Then: got the doc fees reimbursed w/ a $100 gift card and also got another gift card for $100 since I purchased $1K~ of accessories (at 10% off MSRP with free installation).
All +TTL
Others report similar. Best deals I've seen are dealers on EBay. MSRP plus $297. $80 doc fee. But, then it's shipping or travel considerations.
Mainly, finding the unit you want is hardest. My dealer says the 2 and 3 UP HO w/ ibr seem to be hottest. I wanted a base 60HP in yellow and got the "one" (first sale for my dealer) on display at Costco.
Happy hunting!