Sure, technically it is not that difficult. But you will need to buy two sizes of styrene strips, with each Evergreen set usually over 5 euros.
Or cut them from a sheet and then sand the edges for 80 cm of strips and stack a few to make the bigger inner beams.
And then align and glue everything, and mark the wooden texture.
The set is priced at 6 euros. Considering the cost of the materials and time needed to build your own, I think it is an interesting product.