I believe they knew that the popularity for their products being high. As they announced the new GPU's and CPU's, being perfect for any user at any price point (kinda). I think the popularity was higher than expected, similarly to Nvidia, and I think part of this is due to many customers wanting these new, amazingly priced components considering their performance, add to this COVID-19 and you have hundreds of thousands of people wanting to buy their products.
Prices are high because, they can be, and if retailers want to sell their products higher than AMD are selling them for, then they just... can. I personally wouldn't spend more than RRP for the components, however, retailers KNOW that some people will, and some people don't are how much it costs to get a new component in their rig.
I don't think AMD did this on purpose at all, and I think come 2021, more and more stock will become available until eventually there is enough for everyone.
Hope that helped a little.