For a total blade beginner, to start to get familiar with a katana (with its shape, grip and partly with his weight / mobility) without spending too much, we can buy a junk product like the one in the photo.
When we take a low quality / cost product like this, it is extremely important to keep in mind some important things:
Let's make sure that the blade is securely attached to the handle (if not we do not have to buy it)
We will never be able to use it against other swords, walls, floors, to cut, etc. (it will immediately bend or, worst, it will be splitted in 2 pieces)
We must not try to sharpen it, this is expensive, dangerous and useless (probably it will also rust in a few days)
We must not touch the blade with bare hands (it will rust rapidly)
We have to keep it oiled each time we use it (for these not-stainless-steel blades is fine first price linseed oil)
One day the blade will start inevitably to bend easily (after 2-12 months), from that moment let's absolutely stop using it
Let's never try to use it at full speed / power, only at a slow pace to undestand what this wepon is and how it works (nothing more)
Even if it is only an poor iron bar we have to be careful as if it was a real blade
This junk products are not for sparring / training / etc. but only for exposition purpose
The good thing is that a novice can explorate the idea of "katana" without risks (some razor blade shinken katana can cut a single hair only falling on it) and without wasting too much money (generally less than 25?).
Said this it is important to stress the fact that professional products are totally different about:
Point of balance (perfectly calibrated, not casual)
Internal / external blade's structure (to obtain a good balance between solidity and flexibility)
Quality checkings (good blades are tested before being sold)
Resistence to traction / impact / etc. (they are guaranteed for high stress)
Materials (eg. stainless steel 1095)
Assembling precision / solidity (precise controls and parametrizations)
Metal treatment (coldening, etc.)
Price (good practical katana starts at least from 250?)
Durability (potentially they will live forever)
In future articles we will see some other cheaper alternative products to the professional ones (always describing limits and opportunities).