Warning, some of the ending to the game is shown in the screenshots down below.
Not that I think many people are concerned about Dragon Warrior spoilers, but if one were I'd had to be the guy that ruined this game for someone else.
When I was five I only had a few NES games: Mario/Duck Hunt, Zelda, Friday the 13th, Karnov, Adventure Island II, and Dragon Warrior. I might like other games more than these, but somewhere deep in my subconsciousness these things are permanently etched into my brain.
So it's always fun to go back and re-explore the kingdom of Alefgard. This time I didn't even stop to take names, just grabbed all the Erdrick equipment at level 14 and then grinded my way to 20. I tried to beat the Dragonlord at 17, 18, and 19. No dice. Although certainly possible to do, it was absolutely impossible to defeat the Dragonlord without relying on at least 2 "coinflips." Essentially I was looking at something of a 25% success rate given my characters stats. I decided I'd rather spend the 30 minutes grinding from 19 to 20. If I had just done that in the first place it would have been much faster, but less fun.
If you want to complete the game quickly, you need to skip about 40% of the purchasable upgrades. As far as weapons go, avoid the bamboo pole; it's too weak and the club is better. Also avoid the Flame Sword, you do not need it; instead buy the Silver Shield as soon as you can, because you will use this for the rest of the game.
You also do not need to buy the Chain Armor or Full Plate. Instead only get Leather, Half, Magic. You could get Full Plate instead of magic armor, but I found that the extra 5000 gold was not too hard to get when fighting Goldmen and Wyverns south of Rimuldar.
The Axe Knight can be difficult, but I got a crit on him which gave me the armor early. I would suggest several attempts at him using repel water, and reset if you die. Rumors exist that sleep can work, but good luck with that.
Adding more party members to the game just slows down the formula. I wish more RPGs actually felt like you were the character, not some Starcraft Overmind issuing commands to an army of wizards and warriors.
On to Dragon Warrior II.