Newer Sony Models are $20 to unlock and can only be unlocked by IMEI Code.
Unlock codes can take up to 4 hours to get.
W810i, w580i ...
Older Sony Ericson Models $10 to Unlock:
These models are $10 to unlock.
Sony Ericsson:
W600i W550 Z520 Z500 S710a, V800, K300i, K300c, K500i, K500c, K506c, K508i,
K508c, K700i, K700c, S700i, S700c, Z1010, T637, T630, T628, Z200, Z600, Z608,
P900, P908, T600,T602, T226, T226s, T230, T237, T238, T618sc,T616, T618, T610,
T600, T66c, T66, P802, P800, T316, T310, T310c T306, T302, T300, T202, T200,
T100, T100c, T106, T68i, T68is, T68ie, T68ic, T68, T68m, T68mc, T39, T39m,
T39mc, T65s T65sc, T65, R600s, R600sc, R600, R520mc, R520m, R520, A3618sc,
A3618s, A3618, A2618, A2628, A2218z, T20, T29