The cost of 2 hanging spring swirls is 2 * $14.99 = $<<2*14.99=29.98>>29.98.
The cost of 5 hanging butterflies is 5 * $13.99 = $<<5*13.99=69.95>>69.95.
The cost of 10 flower cutouts is 10 * $11.99 = $<<10*11.99=119.90>>119.90.
The cost of 4 butterfly window clings is 4 * $10.99 = $<<4*10.99=43.96>>43.96.
The total cost is $29.98 + $69.95 + $119.90 + $43.96 = $<<29.98+69.95+119.90+43.96=263.79>>263.79. Answer: \boxed{263.79}.