You could keep an RNG element In this if you really wanted. Don't see why we need It at all but you could add it by.
A) You make all upgrades available but you have rounds were some items are at a discount. The discount is the normal cost of atm but all other upgrades are available with a 10-25% "tax". This would reward patience but still gives people the option to craft it then an there at the cost of paying more.
B) You make all upgrades available but you have rounds were some items are easier to craft. By easier to craft I mean the rounds would put some upgrades at the levels we know 25, 28, 30 but all the upgrades can be found at 32, 35, 37. This would give a reason to help level up house crafting atm. You could maybe make the round items on personal crafting rather than house crafting so Blacksmith, Armorsmith and same levels 25, 28, 30.
A) You make all upgrades available but you have rounds were some items are at a discount. The discount is the normal cost of atm but all other upgrades are available with a 10-25% "tax". This would reward patience but still gives people the option to craft it then an there at the cost of paying more.
B) You make all upgrades available but you have rounds were some items are easier to craft. By easier to craft I mean the rounds would put some upgrades at the levels we know 25, 28, 30 but all the upgrades can be found at 32, 35, 37. This would give a reason to help level up house crafting atm. You could maybe make the round items on personal crafting rather than house crafting so Blacksmith, Armorsmith and same levels 25, 28, 30.