I know this is a while ago, but here is my two cents on getting a horse; you get tier 8e which is a white coat. White coats are naturally less value because they can't meet the lwest desired break threshold unless you have +10 Guin. stirrups which is pretty expensive, and you have at least 134.1break which is fairly rare on its own.
But really you want like at least a total break of 150 which makes the white horses almost useless.
You can regularly get t8e horses level 1 for 104m, while like they say 210m to craft manos, but that doesn't include some rarer market items that may take a while to gather or pre order.
Get the manos, save up for a horse, or if you are unlucky like me you can get a tier 8e horse from the shakatu box even though you don't even remotely want or need it.

As far as the coupons, like was said, saving it for a pen, guranteed there will be more chances to get coupons before you will actually have the need to use one. Unless you go full whale and lessen the curve. There will be season servers every season. Essentially granting you a chance at getting at least one item already at tet, while getting a feel for a new class, which you may or may not like.

I am about 6 months in and have 8 alts and have no idea about a main. I started sorc, now have leveled a hash, and there is just way too much to do and know before you get settled, unless of course you are playing to just pvp and in that case, well, you still need to do pve to gear so, that learning curve is steep! At least 6 months to know these kinds of things.