Track the latest prices at the New York Fulton Fish Market.  You may want to convert the prices to price per piece.  For example, in the pricelist below, Massachusetts top necks were selling for $35 for a bag of 200; $35 divided by 200 pieces gives a price of 17.5 cents each.  

Unless otherwise stated, bags of chowders are 100 count, cherries are 150 count, top necks are 200 count, and little necks are 400 count.

Below is a sample of the shellfish price information from Friday, February 22, 2002.  Shellfish prices are on the second half of the page, below finfish.

PRIMARY WHOLESALE SELLING PRICES ON NEW YORK FULTON FISH MARKET

FRIDAY, FEB. 22, 2002

SHELLFISH: Supply moderate with carry over, market about steady, not sold out.

Note: BAGS= chow=100cnt; cherrys=150cnt; top necks=200cnt;necks= 400cnt unless otherwise stated.

CLAMS: HARD(BAGS): Sup mod w/c/o, mkt abt stdy, nso. NY(LI) & Ct chow $13-15, cherrys $23-25, top necks $40, necks $90. RI necks $90. NJ chow $12, cherrys $22, top necks $35, necks $80. MA cherrys $22, top necks $35. Fla necks $75.
CLAMS: SOFT(BU): Sup lt, mkt abt stdy. Me $100.
CLAMS: SURF,SHKD(GAL): Sup lt-mod w/c/o, mkt abt stdy. RI minced $17.
COCKLES: Sup lt w/c/o, mkt abt stdy. N.Z'land. (air) $2.35/lb.
CRAB MEAT: Sup lt w/c/o, mkt abt stdy. Md jlmp $21, lmp $15.
CRABS,HARD(BU): Sup lt, mkt abt stdy. NY(LI) & NC females $75-80.
CRABS:JONAH: Sup lt, mkt abt stdy. Me $1/lb.
LOBSTERS,LIVE: Sup mod w/c/o, mkt abt stdy, nso. Me 2# $6, 1 1/2# $5.85, 1 1/4#
$5.75, chix $5.75, med & sml culls $5.40.
MUSSELS,BAY(BAGS/BOXES): Sup mod, mkt abt stdy, nso. MA lge $15. Me lge $13. Me 75/lb. P.E.I. (cultivated) $1/lb. N.Z'land. (air) $2.35/lb.
OYSTERS:SHELL(BOXES): Sup lt, mkt abt stdy. Ct (cultivated) 200cnt $80. MS (wild) 100cnt $19.
OYSTERS:SHKD(GAL): Sup lt, mkt abt stdy. Md selects $48.
SCALLOPS:SEA: Sup mod, mkt abt stdy, nso. MA(N.Bed.) Un/10 cnt $5, 10/20 cnt $4.50, 20/30 cnt $4, 30/40 cnt $3.50. NJ dry Un/10 cnt $9.25, 10/20 cnt $6, 20/30 cnt $5.25.

SQUID(LOLIGO): Sup mod, mkt abt stdy, nso. NJ lge $1.65-1.70 sh/sl a/q, mxd 65-70 a/s/q. NY(LI) mxd 65-70 a/s/q.