Is other send with effects in iMessage available for purchase?

Use message effects with iMessage on your iPhone, iPad, and iPod touch

Make your iMessages even more expressive with bubble effects, full-screen animations, camera effects, and more.

You need iMessage to send message effects. If you aren't sure whether you're using iMessage or SMS/MMS texts, learn the difference. Depending on your carrier, messaging rates might apply when you send SMS/MMS. If you use iMessage and Wi-Fi is unavailable, cellular data rates might apply.

Send a message with effects

With message effects, you can use bubble effects to change the way your message bubbles look. You can also use full-screen effects to animate the screen when you send a message.

Add a bubble effect

You can use bubble effects to animate your message bubbles with different expressions. To send a message with a bubble effect, follow these steps:

1. Open Messages and tap  to start a new message. Or go to an existing conversation.
2. Enter your message or insert a photo, then touch and hold .
3. Tap  to preview bubble effects.
4. Tap  to send.

To replay a message effect that you receive, tap  under the message. If you can't receive bubble effects, check your Reduce Motion settings.

Add a full-screen effect

With full-screen effects, you can animate your screen with an echo, spotlight, and other effects. Follow these steps:

1. Open Messages and tap  to start a new message. Or go to an existing conversation.
2. Enter your message. 
3. Touch and hold , then tap Screen.
4. Swipe to the left to see full-screen effects.
5. Tap  to send.

To replay a message effect that you receive, tap the  under the message. If you can't receive full-screen effects, check your Reduce Motion settings.

Use message effects with iMessage on your iPhone, iPad, and iPod ...

https://support.apple.com/en-us/HT206894

No, there are not other effects available for purchase.