- On the lower levels there is little incentive to use gold to intsabuild wheatfields since the time it takes to collect the amount of resources is larger than the time it takes to build the field if you mainbuilding has a high enough level.
- If you're granary is large enough you can collect enough wheat to NPC for 2 fields which saves money if you are indeed instabuilding wheatfields.
- If you build a lvl 15 wheatfield it takes 328070 resources but 26245 of this amount is wheat. So your granary only needs to have a capacity of 301825. at 301825 you NPC for the wood/clay/iron and then you wait for the wheat to fill up too 26245.
- That last tips also works if you are NPC'en for 2 wheatfields at once.
- Try to have some extra granary capacity so after you NPC for wheatfields you can use the resources to buildup other infrastructure.
This puts us on (wood/clay/iron included);
lvl 0 -> 13 = 234 buildings / 2 = 117 NPC (NPCing for 2 wheatfields at the time)
lvl 14-15 = 36 buildings / 1 = 36 NPC (NPCing for 1 wheatfield at the time)
lvl 15 -> 16 = 18 buildings * 1,5 = 27 NPC (NPCing 1,5 times per field)
lvl 16 -> 17 = 18 buildings = 36 NPC (NPCing 2 times per field)
for a total of 216 NPC's. Now lets say you start instabuilding from lvl 10 fields so lvl (17-10) * 18 fields = 126 buildings = 63 instabuilds IF you instabuild 2 at the same time. NPC = 3 gold and instabuild = 2 gold so (63*2) + (216*3) = 774 gold. Lets make it an even 800.
This only works if you have the 25% bonus and PLUS (for instabuilding 2 wheatfiels at once) so 100 days little under 15 weeks so thats another 450 gold on bonuses. You can however shave a little of the top via those daily tasks. 100 days before arti's = 100 days of free bonuses = about 14 weeks of free stuff for 1 type of bonus. Now PLUS is a little more expensive than a resource bonus so it saves at least 14*5 = 75 gold but could be more depending on how many times you hit the jackpot (PLUS).
Anyway that's 800 + 450 - 75 = 1175 gold. Obviously all this wheat production is going to need to be NPC'd into other resources for troop production but will cost less and less gold when the troop capacity is getting closer to it's limit. Lets say you're building 1 hammer which is gives you 2144 worth of wheat in troops per day, you have 480k granary capacity and produce 84300 wheat (100% 15c - 1k wheat for inhabitants). This comes down to: 24 / (480000 / (84300 – 2144 * x)) with x being the numbers of days you're building that hammer. You can plot a graph in google but assuming you NPC at least once a day and started building that hammer by day 40 that'd cost you another 258 gold which adds up to a total of 1333 gold for 100 days of Travian. 3 bucks a week 
