Hi,
For the product you gave in your pm you configured several prices with different quantities for the public and registered user groups.
So anonymous users (not logged in), and standard registered users (after login) will see these prices and the prices will change based on the quantity purchased.
And that works fine as far as I can see on your website.
Now you also set some prices for that product with a minimum quantity of 1 and a specific user group. So this means that regardless of the quantity purchased, the users from these user groups will get that price. If you also want quantity pricing for these user groups, then you should also add several prices with different minimum quantity like you did for public/registered users.
Also, if you login with a user that is both registered and in a wholesaler user group, he will actually see all the prices of the registered user group and the wholesaler user group. So make sure that this is not the case since you don't want that.
Finally, in your pm you say that you want a discount of 30% on all the prices for the wholesaler user group. In that case, it is way easier to setup than what you're trying to do. Instead of configuring different prices for different user groups, just have one set of prices (for the different minimum quantities) for all the user groups and then go in the menu Orders>Discounts and configure one discount of 30% and restrict it to the wholesaler user group. Then, all the prices will automatically and dynamically get the 30% rebate if you're logged in with a user attached to that user group, and even if you're also from the registered user group it won't matter.
Now you also asked about guest checkout. When you place an order as a guest, you're considered by the system as from the user group "public", always. So wholesaler will have to first create a user account on your website and you will first have to add them to their wholesaler user group so that they can benefit from the 30% discount.
Of course, once you're logged in, either as a registered user or a wholesaler user, you cannot guest checkout since you're already logged in a HikaShop doesn't show anymore the guest checkout form since it is not needed as you're already identified.