7100 gold is such a weird nunber, how about around 7100 since you should be able to wait 10 seconds at the shop + usually I am upgrading items too so it is not so clear how much money you have available at any given time?
3x Bramble Shield
3x Ground Spikes
1x Spike Wave
Boots of Speed
Sell Banded Armor get Hauberk
Sell Scaled Helm Get Plenor Battle Crown
You might scoff at universal gadget, but for this build it is very easy to get a surprise kill. Just keep shielding until the enemy begins to withdraw, then chase and keep hitting since you are faster. If you can kill them before they get to their towers, great. If they reach the towers, try and get him to >650 life and then pop him.
Plenor is also more useful then faceguard if you plan on using ground spikes, spike wave and then shielding. You can burn alot of mana in one attack, so the extra 500 mana is better if you want to be able to shield because you took alot of damage in the initial exchange and your shield was collapsed. It also gets you closer to wyrmskin, since it is cheaper. When you have wyrmskin and do a ground spike + spike wave, there is usually no escape if they try and withdraw.