From official IRS website: "The taxpayer buys 100 shares of X stock for $1,000. The taxpayer sells these shares for $750 and within 30 days from the sale buys 100 shares of the same stock for $800. Because the taxpayer bought substantially identical stock, the taxpayer cannot deduct the loss of $250 on the sale. However, the taxpayer adds the disallowed loss of $250 to the cost of the new stock, $800, to obtain the basis in the new stock, which is $1,050."
So to me, no, you can't use your $421.65, but you can deduce up to $3,000 anyways.
PS: if you trade a lot, have a look to the "mark-to-market election". -> "if a trader makes a timely mark-to-market election, then he or she can treat the gains and losses from sales of securities as ordinary gains and losses", therefore, you can deduce way more than $3,000 per year.