The first run of the magazine was priced at 25 cents for the first fifteen years of its life except for the oversized May/June/July 1924 issue, which was 50 cents.  In September 1939 the price was reduced to 15 cents, where it stayed until the September 1947 issue, which was 20 cents.  The price went up again to 25 cents in May 1949; the digest-sized issues from September 1953 to September 1954 were 35 cents.  The first three paperbacks edited by Lin Carter were priced at $2.50; the fourth was $2.95.  The two Bellerophon issues were $2.50 and $2.95.  The Terminus Weird Tales began in Spring 1988 priced at $3.50; this went up to $4.00 with the Fall 1988 issue, and to $4.95 with the Summer 1990 issue.  The next price increase was to $5.95, in Spring 2003, and then to $6.99 with the January 2008 issue.  The first two issues from Nth Dimension Media were priced at $7.95 and $6.99; the last two were $9.99 each.
Question: How many dollars would it have cost to buy the Summer 1990, Spring 2003 and January 2008 issues of the Terminus Weird Tales?
Answer: 17.89