The type of system (and therefore the cost) you install depends greatly upon your intention and your usage pattern.
For example: -
You have a retail outlet and an EV which you can charge during the day.
A basic grid-tie system whereby the energy is used as soon as it's made (running the A/C and charging the car) would make sense (even with no export/net-metering in place).
At the other end of the scale.
You have a home that's empty all day with only minimal daytime consumption (fridge/freezer, fish tank pump etc.), so you need to time-shift your energy.
You can do this with an ESS (Energy Storage System = Batteries = $$$) or by exporting to the grid during the day and re-importing at night **
Most of us fall somewhere in between the two extremes.
** The official way of doing this is to have a Feed in Tariff (FIT) which currently pays about 50% of the retail cost for each kWh you export, of course you pay full retail cost when you re-import that kWh. Unfortunately, the restrictions on installation contractors, equipment approval and the like mean that this is a non-starter for DIY and therefore significantly increases the system cost (to the point where DIY with a decent sized ESS could be economical).
** The rather less official way of doing this (assuming you have a conventional disc-type meter) is to simply spin the meter backwards whilst exporting, you effectively get the full retail value of every kWh you export.
This is of course illegal, but it's how probably millions of small systems operate in Thailand and to a large degree the authorities tolerate it. It's how we operate once our batteries are full, it's a shame to waste our excess production ???? Just ensure that you never actually end up as a net-exporter (-ve monthly use) and that the meter reader never sees the meter going backwards. I've never heard of anyone who got caught out getting more than a slapped wrist and the installation of a no-reverse meter.