It probably is well known, but worth to reiterate:
Do not just upgrade to buying some Logos 9 packages from the website if you bought any Logos 8 packages within 30 days.
In the case that your upgrade package includes everything included in the previous package, you can return and buy it later. It will saves you some money.
In any cases (including the above case), you can actually contact sales directly, tell them you bought Logos 8 in the last 30 days, and if they do it correctly to adjust the pricing, it will be equivalent to the above case (if the upgrade package includes the returning package), or do something smarter (if the 2 packages has mutually exclusive titles.)
However, you might not be sure “if they did correctly”, so a return is cleaner. In my case, it was Logos 8 Academic Professional to Logos 9 Academic Professional:
- paid $236.56 for Logos 8 AP
- upgrade to Logos 9 AP library only is $17.09
- including full feature set is 151.76
After I return it,
- upgrade to Logos 9 AP library only is $244.73
- including full feature set is $379.40
The diff is not a lot, but the point is it is less expensive in total after return.
Also, I checked earlier that Logos 9 AP strictly includes Logos 8 AP. But they changes Logos 9 AP a couple of time. I think it still holds, but I could check again.
Edit: Warning: if the product you return is not included (i.e. not a subset of) the product you are upgrading to, you are losing resources. I thought it was clear from the text above, but some of you said otherwise. Be warned.