Wanting to find an inexpensive 'cheaper' charger that is also one of the better chargers is a wish.
The best most reliable chargers that are aided with their digital control circuits will have a more traditional power source design still utilizing large transformers. That means heavy amounts of copper which quickly adds significantly to the costs. If you have a good amp output recent year battery charger that is also quite heavy, you surely have such a charger. A Dual Pro 4 bank onboard charger can weigh ~75 lbs.
If you instead consider one of the small, lightweight chargers (NOCO for example) that make claim to supply a high amp output, it will not have any heavy copper transformers and instead must use high frequency switching technology to deliver their amps. They may not supply their rated outputs continuously. Such chargers often tend to operate quite near the limits of their electronic components as may later be seen in their failure rates. Any pulse technology outputs from such chargers that during battery charging reaches left connected boat electronics may have damaging consequences.
If you want to purchase a good reliable charger, be sure to be aware of the weight of the charger when making comparisons and unless copper prices plummet, it will not be the most inexpensive.